What kind of steel are rails made from: a review of materials and technologies
Rails are the most important part of the railway infrastructure, without which it is impossible to imagine modern transport systems. The quality of rails directly affects the safety of train traffic and the durability of the railway track. Therefore, the choice of steel for their production is one of the most critical stages. In order for rails to withstand enormous loads, serve steadily for decades and ensure comfortable movement of the train, it is necessary to use steel with a special composition and properties. Let's figure out what kind of steel rails are made of and which materials are best suited for various operating conditions.
Requirements for steel for rails
Rails are subjected to serious loads every day - from the weight of trains and vibration to weather conditions. Therefore, steel for them must have the following properties:
- High strength and hardness. Rails must retain their shape and withstand heavy loads without deformation.
- Wear resistance. Constant wheel friction creates a high risk of wear, and steel must resist this to extend the life of the rails.
- Impact toughness. Rails must withstand the impacts that occur when rolling stock moves, especially at high speeds.
- Corrosion resistance. In conditions of high humidity, near industrial facilities or seaports, rails are at risk of corrosion. Special additives in steel help protect them from this.
These requirements mean that the choice of steel for rails is strictly limited - only high-strength and resistant materials are suitable.
Main types of steel for the production of rails
Rails are made from carbon and alloy steel, each of which has its own characteristics and is used for different types of tracks. Let's look at the main types of steel that are used for the production of rails.
Carbon steel
This type of steel is widely used in the production of rails for standard sections of track. Carbon steel has high hardness and strength, which allows it to withstand significant mechanical loads. The carbon content of steel (typically 0.6 to 0.8%) makes it an excellent choice for moderate traffic areas where there are no high demands on wear resistance and corrosion protection.
Manganese steel
Manganese is also added to rail steel, which improves its properties. Manganese makes the metal stronger and more wear-resistant, which is especially important on highway sections where traffic is intense and the load on the rails is extremely high. Such steel shows excellent results in conditions of constant contact with train wheels, preventing the formation of cracks and wear.
Alloy steel
In some conditions, especially in areas with an aggressive environment, for example, near industrial zones or seaports, the rails are made of alloy steel with the addition of elements such as chromium, nickel and molybdenum. Each of these metals gives the steel special properties:
- Chrome improves the corrosion resistance of rails, making them more resistant to moisture and chemicals.
- Nickel increases ductility and strength, which reduces the risk of rail destruction due to temperature changes.
- Molybdenum increases strength and wear resistance, especially important for rails used at high speed areas.
Modern rail production technologies
Rail production is a complex and multi-stage process, at each stage of which it is important to strictly comply with technological requirements. Key steps include:
- Steel rolling. The steel billet is heated to a high temperature and passed through rolling mills to give it the desired shape of the rail.
- Heat treatment. Rails are subjected to hardening, which increases their hardness, and tempering to reduce brittleness, providing the desired balance between strength and ductility.
- Quality control. Finished rails are checked for compliance with standards for strength, wear resistance and other important parameters.
Production technologies are constantly being improved. For example, modern rails can undergo thermo-mechanical processing, which involves a combination of rolling and heat treatment to achieve optimal performance.
Quality control: an important aspect of rail production
Important stage is careful quality control. Each batch of rails is tested for compliance with standards such as GOST or other international standards. They check strength, wear resistance, absence of microcracks and defects to make sure that the rails will serve for a long time and safely.
Advantages of high-quality steel for rails
The use of high-quality steel in the production of rails